chapter 11/12 neuroanamony Flashcards
The nervous system
The nervous system (in particular cerebral cortex) is that body system responsible for voluntary activity
The nervous system is the source of
The nervous system is the source of our (unique?) communication ability
Human brains are heavier and more developed than primates
Note, laryngological differences also
Cerebrum
largest mass of brain tissue
Cerebral hemispheres
Left and right hemispheres connected by corpus callosum
CNS (aka neuraxis)
Brain and spinal cord
Housed in bone
PNS
12 pairs cranial nerves + 31 pairs spinal nerves + sensory receptors
Mostly outside of bone
Autonomic nervous system
regulates bodily functions & activity of specific organs (not consciously controlled)
controls vital functions (e.g., respiration and digestion)
Somatic nervous system
: voluntary control of body movements and reception of external stimuli
Somatic: pertaining to the body
Conscious/voluntary control of skeletal mm
2 components of Autonomic Nervous System
Sympathetic
Parasympathetic
Parasympathetic
NS slows and relaxes (“rest and digest”) [damping response following excitation
sympathetic
NS stimulates organs and systems (“fight or flight”) [excitatory response to stimulation
2 components Somatic Nervous System
motor and sensory
motor
neural impulses sent from brain via brainstem and spinal cord by means of tracts (pathways) to periphery [efferent]
sensory
monitoring of information regarding body’s status and the environment sent to the brain [afferent]
Sensation
Sensation begins with the reception of a stimulus by a receptor cell and continues with the passage of information onto the brain
Mechanoreceptors
physical distortion receptors
Chemoreceptors
specific molecules
E.g., Olfaction, gustation
Photoreceptors
light
Thermoreceptors
Temperature
Specific sensory classes
somatic and special
somatic
related to pain, thermal stimulation, mechanical stimulation.
special
involved in changing a stimulus to another form of energy (e.g., gustation, olfaction, vision, hearing)
All structures are constructed from
All structures are constructed from neurons and glia
neurons
Neurons transmit information
glial cells
Glial cells are involved in support functions
Neurons consist
Neurons consist of a cell body/soma, axon and dendrite
Neurons have 2 responses (excitation/inhibition)
A nerve cell in the PNS
ganglion
Neuronal anatomy
Axon: process that transmits info from the soma
Hillock
Myelin sheath [insulation]
Nodes of Ranvier
Terminal end boutons
Neurotransmitter
Dendrite: process that transmits info to the soma
Synaptic cleft: region between 2 communicating neurons
Axons are covered with
myelin sheaths
Schwann
cells make PNS myelin
Oligodendrocytes
make CNS myelin